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Abstract:

A system for treating an aneurysm comprises an elongate flexible shaft
and an expandable member. An expandable scaffold is disposed over the
expandable member and may be expanded from a collapsed configuration to
an expanded configuration. A double-walled filling structure is disposed
over the scaffold and has an outer wall and an inner wall. The filling
structure is adapted to be filled with a hardenable fluid filing medium
so that the outer wall conforms to an inside surface of the aneurysm and
the inner wall forms a substantially tubular lumen to provide a path for
blood flow. In the expanded configuration the scaffold engages the inner
wall of the filling structure. A tether is releasably coupled with the
filling structure and the flexible shaft thereby constraining axial
movement of the structures relative to each other.

Claims:

1. A system for treating an aneurysm in a blood vessel, the system
comprising: an elongate flexible shaft having a proximal region and a
distal region; a first double-walled filling structure disposed over the
distal region of the shaft, the filling structure having an outer wall
and an inner wall, wherein the filling structure is adapted to be filled
with a hardenable fluid filing medium so that the outer wall conforms to
an inside surface of the aneurysm and the inner wall forms a first
substantially tubular lumen to provide a path for blood flow; and at
least a first expandable scaffold disposed adjacent the filling
structure, the first scaffold radially expandable within at least a
portion of the tubular lumen of the filling structure.

Description:

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.
13/243,941 filed on Sep. 23, 2011, which is a divisional of U.S.
application Ser. No. 12/429,474 filed on Apr. 24, 2009, which is a
non-provisional of, and claims the benefit of U.S. Provisional
Application No. 61/048,038 (Attorney Docket No. 025925-002600US), filed
on Apr. 25, 2008, the full disclosures of which are incorporated herein
by reference.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT

[0002] NOT APPLICABLE

REFERENCE TO A "SEQUENCE LISTING," A TABLE, OR A COMPUTER PROGRAM LISTING
APPENDIX SUBMITTED ON A COMPACT DISK

[0003] NOT APPLICABLE

BACKGROUND OF THE INVENTION

[0004] 1. Field of the Invention

[0005] The present invention relates generally to medical systems and
methods for treatment. More particularly, the present invention relates
to systems and methods for treating aneurysms.

[0006] Aneurysms are enlargements or "bulges" in blood vessels which are
often prone to rupture and which therefore present a serious risk to the
patient. Aneurysms may occur in any blood vessel but are of particular
concern when they occur in the cerebral vasculature or the patient's
aorta.

[0007] The present invention is particularly concerned with aneurysms
occurring in the aorta, particularly those referred to as aortic
aneurysms. Abdominal aortic aneurysms (AAA's) are classified based on
their location within the aorta as well as their shape and complexity.
Aneurysms which are found below the renal arteries are referred to as
infrarenal abdominal aortic aneurysms. Suprarenal abdominal aortic
aneurysms occur above the renal arteries, while thoracic aortic aneurysms
(TAA's) occur in the ascending, transverse, or descending part of the
upper aorta.

[0008] Infrarenal aneurysms are the most common, representing about eighty
percent (80%) of all aortic aneurysms. Suprarenal aneurysms are less
common, representing about 20% of the aortic aneurysms. Thoracic aortic
aneurysms are the least common and often the most difficult to treat.

[0009] The most common form of aneurysm is "fusiform," where the
enlargement extends about the entire aortic circumference. Less commonly,
the aneurysms may be characterized by a bulge on one side of the blood
vessel attached at a narrow neck. Thoracic aortic aneurysms are often
dissecting aneurysms caused by hemorrhagic separation in the aortic wall,
usually within the medial layer. The most common treatment for each of
these types and forms of aneurysm is open surgical repair. Open surgical
repair is quite successful in patients who are otherwise reasonably
healthy and free from significant co-morbidities. Such open surgical
procedures are problematic, however, since access to the abdominal and
thoracic aortas is difficult to obtain and because the aorta must be
clamped off, placing significant strain on the patient's heart.

[0010] Over the past decade, endoluminal grafts have come into widespread
use for the treatment of aortic aneurysm in patients who cannot undergo
open surgical procedures. In general, endoluminal repairs access the
aneurysm "endoluminally" through either or both iliac arteries in the
groin. The grafts, which typically have been fabric or membrane tubes
supported and attached by various stent structures, are then implanted,
typically requiring several pieces or modules to be assembled in situ.
Successful endoluminal procedures have a much shorter recovery period
than open surgical procedures.

[0011] Present endoluminal aortic aneurysm repairs, however, suffer from a
number of limitations. For example, a significant number of endoluminal
repair patients experience leakage at the proximal juncture (attachment
point closest to the heart) within two years of the initial repair
procedure. While such leaks can often be fixed by further endoluminal
procedures, the need to have such follow-up treatments significantly
increases cost and is certainly undesirable for the patient. A less
common but more serious problem has been graft migration. In instances
where the graft migrates or slips from its intended position, open
surgical repair is required. This is a particular problem since the
patients receiving the endoluminal grafts are often those who are not
considered to be good surgical candidates.

[0012] Further shortcomings of the present endoluminal graft systems
relate to both deployment and configuration. For example, many of the
commercially available endovascular systems are too large (above 12 F)
for percutaneous introduction. Moreover, current devices often have an
annular support frame that is stiff and difficult to deliver as well as
unsuitable for treating many geometrically complex aneurysms,
particularly infrarenal aneurysms with little space between the renal
arteries and the upper end of the aneurysm, referred to as short-neck or
no-neck aneurysms. Aneurysms having torturous geometries, are also
difficult to treat.

[0013] For these reasons, it would be desirable to provide improved
methods and systems for the endoluminal and minimally invasive treatment
of aortic aneurysms. In particular, it would be desirable to provide
systems having lower delivery profile and methods which can be delivered
percutaneously and that can track and be deployed in tortuous vessels. It
would also be desirable to provide prostheses with minimal or no
endoleaks, which resist migration, which are flexible and relatively easy
to deploy, and which can treat many if not all aneurismal configurations,
including short-neck and no-neck aneurysms as well as those with highly
irregular and asymmetric geometries. It would be further desirable to
provide systems and methods which are compatible with current designs for
endoluminal stents and grafts, including single lumen stents and grafts,
bifurcated stents and grafts, parallel stents and grafts, as well as with
double-walled filling structures which are the subject of the commonly
owned, copending applications described below. It would also be desirable
to provide systems and methods that provide feedback to the operator as
to the positioning and deployment of the endoluminal repair device in the
aneurysm. The systems and methods would preferably be deployable with the
stents and grafts at the time the stents and grafts are initially placed.
Additionally, it would be desirable to provide systems and methods for
repairing previously implanted aortic stents and grafts, either
endoluminally or percutaneously. At least some of these objectives will
be met by the inventions described hereinbelow.

[0014] 2. Description of the Background Art

[0015] U.S. Patent Publication No. 2006/0025853 describes a double-walled
filling structure for treating aortic and other aneurysms. Copending,
commonly owned U.S. Patent Publication No. 2006/0212112, describes the
use of liners and extenders to anchor and seal such double-walled filling
structures within the aorta. The full disclosures of both these
publications are incorporated herein by reference. PCT Publication No. WO
01/21108 describes expandable implants attached to a central graft for
filling aortic aneurysms. See also U.S. Pat. Nos. 5,330,528; 5,534,024;
5,843,160; 6,168,592; 6,190,402; 6,312,462; 6,312,463; U.S. Patent
Publications 2002/0045848; 2003/0014075; 2004/0204755; 2005/0004660; and
PCT Publication No. WO 02/102282.

BRIEF SUMMARY OF THE INVENTION

[0016] The present invention provides systems and methods for the
treatment of aneurysms, particularly aortic aneurysms including both
abdominal aortic aneurysms (AAA) and thoracic aortic aneurysms (TAA). The
systems may be introduced percutaneously or by surgical cutdown into a
patient and may have an outer diameter ranging preferably from 10 French
to 18 French and more preferably from 12 French to 16 French.

[0017] In a first aspect of the present invention, a system for treating
an aneurysm in a blood vessel comprises an elongate flexible shaft having
a proximal region and a distal region. A first double-walled filling
structure is disposed over the distal region of the shaft and has an
outer wall and an inner wall. The filling structure may be filled with a
hardenable fluid filing medium so that the outer wall conforms to an
inside surface of the aneurysm and the inner wall forms a first
substantially tubular lumen to provide a path for blood flow. The system
also includes a first expandable scaffold disposed adjacent the filling
structure. The first scaffold is radially expandable within at least a
portion of the tubular lumen of the filling structure and the filling
structure is separate from the first scaffold and axially separated
therefrom.

[0018] In some embodiments, the first scaffold may be proximal to the
filling structure while in other embodiments, the first scaffold is
distal to the filling structure. Sometimes there is a gap or spacing
between one end of the first scaffold and one end of the filling
structure. The first scaffold may be slidably received by the filling
structure so that the first scaffold and the filling structure are
concentric with one another, and the filling structure provides a
covering around the scaffold.

[0019] Sometimes the delivery system may include a sheath that is disposed
at least partially over the filling structure and/or the scaffold. The
sheath may have a tapered tip and may have axially oriented slits. The
system may also include a pusher tube that is disposed at least partially
over the flexible shaft and that slidably engages with the first
double-walled filling structure. A first tether may be coupled with the
filling structure and the tether may extend between the proximal and
distal regions of the flexible shaft. The tether may be adapted to guide
movement of the first double-walled filling structure relative to the
first scaffold axially along the shaft. The tether may also be used to
pull the filling structure as it is axially moved relative to the first
scaffold, thereby slidably engaging and positioning the filling structure
with the first scaffold. Sometimes the delivery system may also comprise
a second tether that is coupled with the filling structure and the second
tether may extend between the proximal and distal regions of the flexible
shaft. Systems may include one or more eyelets or suture loops coupled
with the first filling structure and they may be adapted to receive the
tethers or a tube and act as guides or the filling structure may comprise
a receptacle coupled with a wall of the filling structure that can
slidably receive a tube. The system may also include a nosecone coupled
with the distal region of the flexible shaft and sometimes the tethers
are coupled thereto. Portions of the tether may extend outside of a
patient's body. The tether may be releasably coupled with the filling
structure.

[0020] The system may further comprise an inflation device, such as a
syringe, that is fluidly coupled with the filling structure and a
pressure monitor. The pressure monitor may also be coupled with the
filling structure so as to permit pressure monitoring of the filling
structure as the filling structure is filled with the hardenable fluid
filling medium. The pressure monitor may comprise a pressure gage, a
digital display or the like.

[0021] Sometimes the filling structure comprises a relief valve and an
optional reservoir may be fluidly coupled thereto. The relief valve may
be fluidly isolated from the first filling structure and the reservoir
may be adapted to receive the hardenable fluid filling medium from the
relief valve at a predetermined pressure. The reservoir may be radiopaque
when at least partially filled with the hardenable fluid filling medium.
Other embodiments of the system may have a visual indicator fluidly
coupled with the filling structure. The visual indicator may have first
and second positions wherein the indicator moves from the first position
to the second position when a predetermined pressure is applied to the
visual indicator. This indicator may be visible under fluoroscopy.

[0022] Other embodiments may comprise a collapsible member such as a
balloon that is fluidly coupled with a pressure gage. The collapsible
member may be positioned between the outer wall of the filling structure
and the inside surface of the aneurysm and thus the pressure gage
indicates the pressure of the filling structure as it is filled. Other
embodiments may also include a collapsible member such as a balloon that
is similarly positioned between the aneurysm wall and the filling
structure wall, and that is fluidly coupled with a compression mechanism,
such as a spring, having first and second positions. The compression
mechanism provides a predetermined force opposing the force exerted by
the collapsible member as the filling structure is filled. The
compression mechanism moves from the first position to the second
position when the force exerted by the collapsible member exceeds the
predetermined value. The collapsible member may be a balloon. Some
systems may also include a locking mechanism which prevents fluid from
filling the filling structure when the filling structure is filled to a
predetermined pressure.

[0023] In some embodiments, the filling structure may comprise a compliant
compartment that deforms as the outer wall of the filling structure
conforms to the inside surface of the aneurysm. The compartment may have
a substantially flat section and may be fluidly coupled with a pressure
indicator.

[0024] Sometimes the first or second scaffold may comprise crushable
regions and remainder regions. The crushable regions collapse when the
filling structure is pressurized to a predetermined value while the
remainder regions remain fully expanded. In yet other embodiments, the
system may further comprise an expandable member such as a balloon, that
expands from a contracted configuration to an expanded configuration and
that is coupled with the shaft near the distal region. The expandable
member may be fluidly coupled with a pressure monitoring device. The
expandable member may have a pre-shaped, curved or tapered region.

[0025] The scaffold may be comprised of a metal and may be balloon
expandable. The scaffold or filling structure may also carry a
therapeutic agent that can be released therefrom in a controlled manner.
Some therapeutic agents include anti-thrombogenics like heparin or agents
which promote endothelial and smooth muscle cell growth, sealing and
attachment. The filling structure may comprise a polymer.

[0026] The system may also comprise a second double-walled filling
structure having an outer wall and an inner wall. The double-walled
filling structure may be placed adjacent the first filling structure in
the aneurysm and may be filled with a hardenable fluid filling medium so
that the outer wall conforms to the inside surface of the aneurysm and to
the first filling structure and forms a second generally tubular lumen to
provide a path for blood flow. The system may also include a second
scaffold separate from the first scaffold and the filling structures
which can be expanded within at least a portion of the second tubular
lumen of the second filling structure. The second scaffold may be axially
separated from the second filling structure. Both the second scaffold and
the second filling structure generally take the same form as the first
scaffold and first filling structure. A flowable polymer that may be
cured in situ may be used to as the filling material for both the first
and second filling structures.

[0027] The system may also comprise a releasable coupling mechanism that
is coupled with the first filling structure and the shaft. The coupling
mechanism is adapted to reduce axial movement along the shaft of the
filling structure relative to the scaffold. The releasable coupling
mechanism may comprise a tether that is releasably coupled with the shaft
and the filling structure. The filling structure may also comprise a
filling tube that is fluidly coupled therewith and that is adapted to
fill the filling structure with the filling medium. The filling tube may
also comprise an inner tube that is slidably disposed in the filling
tube. Both the inner tube and the filling tube may be fluidly coupled
with the filling structure.

[0028] In another aspect of the present invention, a method for treating
an aneurysm comprises providing an elongate flexible shaft having a
proximal end and a distal end. The flexible shaft carries a first
double-walled filling structure and a first scaffold adjacent the distal
end. Advancing the elongate shaft in a patient's vasculature allows the
first double-walled filling structure to traverse the aneurysm. Filling
the first filling structure with a fluid filling medium expands the
filling structure so that an outer wall of the first filling structure
conforms to an inside surface of the aneurysm and an inner wall of the
first filling structure forms a first substantially tubular lumen to
provide a first blood flow path across the aneurysm. Axially moving the
first scaffold relative to the first filling structure positions at least
a portion of the first scaffold within the first substantially tubular
lumen and radially expanding the first scaffold expands the first
scaffold from a contracted configuration to an expanded configuration.

[0029] Axially moving the first scaffold may comprise moving the first
scaffold distally into the first lumen or axially moving the first
scaffold may comprise proximally retracting the first filling structure
over the first scaffold. Axially moving the first scaffold may also
comprise proximally retracting the first scaffold into the first lumen or
moving the first filling structure distally over the first scaffold.
Sometimes axially moving the first scaffold may comprise guiding the
first filling structure over a tether line or pulling the first filling
structure with a tether line. The method may also include retracting a
sheath from the first filling structure or the first scaffolding so that
that portion is unconstrained from expansion. The method may also
comprise engaging a pusher tube with the first filling structure so as to
prevent motion thereof. The method may also further comprise hardening
the filling medium in the first filling structure.

[0030] The method may also include monitoring a pressure or controlling
the filling of the first or second filling structures by changing
pressure or volume of the filling medium. Filling the filling structure
may comprise controlling pressure and/or volume of the filling medium.
The pressure may be one that is exerted by the filling medium within the
first filling structure. The monitored pressure may also be a pressure
that is within a space between an external wall of the first filling
structure and a wall of the aneurysm. Monitoring the pressure may include
placing a fluid filled balloon catheter or a pressure transducer in the
space between the filling structure and aneurysm wall. Often, the method
may further include regulating flow of the filling medium in response to
the monitored pressure.

[0031] Filling the filling structure may include actuating an injection
device and pressure may be monitored at a position adjacent the injection
device. The method also may include relieving pressure in the filling
structure with a relief valve when the pressure exceeds a predetermined
value. Sometimes, the relief valve may be fluidly isolated from the first
filling structure. The fluid relieved from the filling structure may fill
a reservoir that is fluidly coupled with the relief valve and an operator
may observe the reservoir to determine inflation status of the filling
structure. Some pressure monitoring devices may include a visual
indicator that is coupled with the first filling structure. The indicator
may have a first and a second position, and the indicator moves from the
first position to the second position when a predetermined pressure is
applied to the indicator. An operator may observe the indicator position
to determine fillings status of the filling structure.

[0032] Other embodiments may include positioning a collapsible member such
as a balloon between the outer wall of the filling structure and the
inside wall of the aneurysm. An operator observes a compression mechanism
having first and second positions that is coupled with the filling
structure. The compression mechanism provides a predetermined force
opposite to the force exerted by the collapsible member as the filling
structure is filled and the compression mechanism moves from the first
position to the second position when the force exerted by the collapsible
member exceed the predetermined force. The compression mechanism may
comprise a spring and the collapsible member may be comprise a balloon.

[0033] The method may also include the step of stopping the filling of the
filling structure when the monitored pressure reaches a predetermined
pressure. Stopping filling may be achieved by mechanically locking a
filling device so that fluid may not be delivered therefrom. Monitoring
pressure may also include observing the first scaffold. The first
scaffold may have crushable regions and remainder regions and the
crushable regions collapse when the filling structure is pressurized to a
predetermined value while the remainder regions remain fully expanded.

[0034] The method may further comprise providing a second elongate
flexible shaft having a proximal and distal end. The second shaft carries
a second double walled filling structure and a second scaffold adjacent
the distal end. Advancing the second elongate shaft in the patient's
vasculature allows the second double walled filling structure to traverse
the aneurysm. Filling the second filling structure with a fluid filling
medium expands the filling structure so that an outer wall of the second
filling structure forms a second substantially tubular lumen to provide a
second blood flow path across the aneurysm. Filling the second filling
structure may also comprise controlling pressure or volume of the fluid
filling medium. Axially moving the second scaffold relative to the second
filling structure positions at least a portion of the second scaffold
within the second substantially tubular lumen and radially expanding the
second scaffold expands the scaffold from a contracted configuration to
an expanded configuration.

[0035] Axially moving the second scaffold may comprise moving the second
scaffold distally into the second lumen or proximally retracting the
second filling structure over the second scaffold. Axially moving the
second scaffold may also comprise proximally retracting the second
scaffold into the second lumen or moving the second filling structure
distally over the second scaffold.

[0036] The method may also comprise retracting a sheath from either the
second filling structure and/or the second scaffolding so that either or
both are unconstrained from expansion. Retracting the sheath may also
comprise splitting the sheath. The method also may comprise hardening the
fluid filling medium in the second filling structure and monitoring a
second pressure. The second pressure may be exerted by the filling medium
in the second filling structure. Often, the flow of the filling medium
may be regulated in response to the second monitored pressure. In some
embodiments, the method may comprise filling either the first or the
second filling structure until it engages the other filling structure
resulting in filling medium being discharged from either the first or
second filling structure. In still other embodiments, the method may
comprise inflating a balloon on either the first or the second elongate
shaft so as to compress the first and second filling structures against
one another and against the aneurysm wall. Often filling medium will be
discharged from either the first or second filling structure when the
balloons are inflated. Radially expanding any of the scaffolds may
comprise inflating a balloon disposed near the distal end of the shaft.
The balloon may comprise a pre-shaped, curved or tapered region.

[0037] The method may also comprise releasing a releasable coupling
mechanism that couples the filling structure with the shaft to allow
axial movement of the filling structure relative to the scaffold and that
also allows release of the filling structure from the shaft. Releasing
the coupling mechanism may comprise releasing a knot in a tether joining
the filling structure with the shaft. A filling tube may be fluidly
coupled with the filling structure and the step of filling the filling
structure may comprise passing fluid filling medium through the filling
tube to the filling structure. The filling tube may comprise an inner
tube that is slidably disposed therein and that is also in fluid
communication with the filling structure. The method may comprise
removing the inner tube and passing additional fluid filling medium
through the filling tube after the inner tube has been removed.

[0038] In another aspect of the present invention, a system for treating
an aneurysm in a blood vessel comprises an elongate flexible shaft having
a proximal region and a distal region. An expandable member is disposed
adjacent the distal region and a first expandable scaffold is disposed
over the expandable member. The first scaffold is radially expandable
from a collapsed configuration to an expanded configuration. A first
double-walled filling structure is disposed over the first scaffold. The
filling structure has an outer wall and an inner wall and the filling
structure is adapted to be filled with a hardenable fluid filing medium
so that the outer wall conforms to an inside surface of the aneurysm and
the inner wall forms a first substantially tubular lumen to provide a
path for blood flow. In the expanded configuration, the first scaffold
engages the inner wall of the filling structure. A first releasable
coupling mechanism releasably couples the filling structure with the
flexible shaft and the coupling mechanism may comprise a tether that is
releasably coupled with the filling structure and the flexible shaft. The
coupling mechanism constrains axial movement of the filling structure
relative to the flexible shaft.

[0039] The first tether may comprise a suture, and in some embodiments the
system may include a lockwire disposed alongside the flexible shaft. A
distal end of the lockwire may be releasably coupled with the flexible
shaft. The flexible shaft may comprise a tapered nosecone having an
aperture therein and the nosecone may be coupled with the distal region
of the flexible shaft such that the distal end of the lockwire may be
releasably coupled with and slidably received in the nosecone aperture.
The first tether may be releasably coupled to the lockwire. The filling
structure may include a first tether loop fixedly attached thereto, and
the first tether may pass through the tether loop. The first tether loop
may be disposed on a distal end of the filling structure. In some
embodiments, the first tether may be releasably coupled to the lockwire
with a knot such as a constrictor knot. One end of the first tether may
be fixedly attached with the flexible shaft.

[0040] The system may further comprise a second releasable coupling
mechanism. The second mechanism may comprise a tether that is releasably
coupled with the filling structure and the flexible shaft. The second
tether may be on an opposite end of the filling structure as the first
tether, and the second tether may constrain axial movement of the filling
structure relative to the flexible shaft. The second tether may comprise
a suture and may be releasably coupled to the lockwire. The second tether
may be looped around the lockwire. In some embodiments, the filling
structure comprises a second tether loop fixedly attached thereto and
disposed on an opposite end as the first tether loop, and the second
tether may pass through the second tether loop. The second tether may be
coupled to the flexible shaft and may be releasably coupled to the
flexible shaft with a knot, such as a constrictor knot.

[0041] The system may further comprise a second releasable coupling
mechanism, such as a tether that is releasably coupled with the filling
structure and the flexible shaft. The second tether may be disposed on
the same end of the filling structure as the first tether, and the second
tether may constrain axial movement of the filling structure relative to
the flexible shaft. The second tether may comprise a suture. In some
embodiments, the system may further comprise a second lockwire disposed
alongside the flexible shaft. A distal end of the second lockwire may be
releasably coupled with the flexible shaft. The distal region of the
flexible shaft may include a tapered nosecone having a second aperture
and the distal end of the second lockwire may be releasably coupled with
and slidably received in the second nosecone aperture. The second tether
may be releasably coupled to the lockwire.

[0042] In some embodiments, the filling structure may comprise a second
tether loop fixedly attached thereto, and wherein the second tether
passes through the second tether loop. The second tether loop may be
disposed on the same end of the filling structure as the first tether
loop. The second tether may be releasably coupled to the lockwire with a
knot such as a constrictor knot. One end of the second tether may be
fixedly attached with the flexible shaft.

[0043] The system may further comprise a filling tube fluidly coupled with
the filling structure. The filling tube may be adapted to deliver the
hardenable filling medium to the filling structure. The filling tube may
comprise a plurality of apertures near a distal end thereof and that are
adapted to allow the hardenable filling medium to flow therethrough into
the filling structure. The filling tube may comprise an inner filling
tube and an outer filling tube slidably disposed thereover, both fluidly
coupled with the filling structure. A stylet may be disposed in the
filling tube. Some embodiments may include a filling tab fluidly coupled
with the filling structure and fluidly coupled with the filling tube. The
filling tab may comprise a scored region adapted to permit separation of
the filling tab into two portions, the first portion remaining coupled
with the filling structure after filling thereof with the hardenable
filling medium and the second portion discrete and independent of the
first portion.

[0044] In still other embodiments, the system may further comprise an
outer sheath having a lumen. The filling structure, the scaffold and the
expandable member may be disposed in the sheath lumen during delivery of
the system to a treatment site. Other embodiments may include a second
elongate flexible shaft having a proximal region and a distal region and
a second expandable member disposed adjacent the distal region. A second
expandable scaffold may be disposed over the second expandable member.
The second scaffold may be radially expandable from a collapsed
configuration to an expanded configuration. The system may also include a
second double-walled filling structure disposed over the second scaffold.
The second filling structure may have an outer wall and an inner wall,
wherein the second filling structure is adapted to be filled with a
hardenable fluid filing medium so that the outer wall conforms to an
inside surface of the aneurysm and the inner wall forms a first
substantially tubular lumen to provide a path for blood flow. The second
scaffold in the expanded configuration may engage the inner wall of the
filling structure, and the system may also have a tether releasably
coupled with the second filling structure and the second flexible shaft.
The tether may constrain axial movement of the second filling structure
relative to the second flexible shaft.

[0045] In yet another aspect of the present invention, a method for
treating an aneurysm in a patient comprises providing an elongate
flexible shaft having a proximal end, a distal end, and an expandable
member near the distal end. The flexible shaft carries a first radially
expandable scaffold over the expandable member and a first double walled
filling structure disposed over the first scaffold. Advancing the shaft
in the vasculature of the patient allows the first filling structure to
be delivered to the aneurysm. Radially expanding the first scaffold
expands the scaffold from a contracted configuration to an expanded
configuration, wherein in the expanded configuration the first scaffold
engages the inner wall of the first filling structure. Filling the first
filling structure with a first fluid filling medium allows an outer wall
of the first filling structure to conform to an inside surface of the
aneurysm and an inner wall of the first filling structure forms a first
substantially tubular lumen to provide a first blood flow path across the
aneurysm. Filling the first filling structure with the first fluid
filling medium also allows assessment of the filling volume by removing
and recording the first filling medium. Filling the first filling
structure with a second fluid filling medium allows an outer wall of the
first filling structure to conform to an inside surface of the aneurysm
and an inner wall of the first filling structure forms a substantially
tubular lumen to provide a first blood flow path across the aneurysm. The
second fluid filling medium is hardened in the first filling structure
and then the first filling structure is released from the flexible shaft.
The flexible shaft is then retracted away from the first filling
structure.

[0046] The method may further comprise pre-filling the first filling
structure with a pre-filling fluid until the outer wall of the first
filling structure conforms to the inside surface of the aneurysm, thereby
unfurling the first filling structure. The pre-filling fluid may comprise
saline and may be removed from the first filling structure. The method
may also comprise pre-filling the first filling structure with
pre-filling fluid until the outer wall of the first filling structure
conforms to the inside surface of the aneurysm. The pressure and volume
of the pre-filling fluid used to pre-fill the first filling structure may
be measured and then the pre-filling fluid may be removed from the first
filling structure. Filling the first filling structure with the first
fluid filling medium may comprise filling the first filling structure
with the first filling medium using substantially the same pressure and
volume as measured. The pre-filling fluid may comprise saline or contrast
media to assist visualizing the filling process under x-ray fluoroscopy.
The first filling medium may be passed through a filling tube that is
fluidly coupled with the first filling structure.

[0047] Radially expanding the scaffold may comprise inflating a balloon
that is disposed on the flexible shaft. Hardening the first fluid filling
medium in the first filling structure may comprise polymerizing the first
fluid filling medium in situ. The first fluid filling medium may comprise
polyethylene glycol.

[0048] A releasable coupling mechanism such as a tether may couple the
first filling structure with the flexible shaft and the step of releasing
the first filling structure from the flexible shaft may comprise
releasing the coupling mechanism or de-coupling the tether from the first
filling structure. One end of the tether may be releasably coupled with a
lockwire and the step of de-coupling the tether may comprise retracting
the lockwire thereby detaching the tether from the lockwire. De-coupling
the tether may comprise releasing the tether from a tether loop on the
first filling structure. In some embodiments, a second releasable
coupling mechanism, such as a tether may couple the first filling
structure with the flexible shaft and the step of releasing the first
filling structure from the flexible shaft may comprise de-coupling the
second tether from the first filling structure. Releasing one or more of
the coupling mechanisms may permit separation of a filling tube from the
filling structure.

[0049] The method may further comprise the step of retracting a sheath
away from the first filling structure and the first scaffold to allow
expansion thereof. Pressure may be monitored during filling of the first
filling structure. The monitored pressure may be a pressure of the
filling medium in the first filling structure or a pressure in a space
between the outer wall of the first filling structure and a wall of the
aneurysm. A filling tube may be released from the first filling structure
after the hardenable filling medium has been delivered thereto. Releasing
the filling tube may comprise severing a filling tab coupled with the
first filling structure.

[0050] In some embodiments, the method may further comprise providing a
second elongate flexible shaft having a proximal end, a distal end, and a
second expandable member near the distal end. The second flexible shaft
may carry a second radially expandable scaffold over the second
expandable member and a second double walled filling structure may be
disposed over the second scaffold. The second shaft may be advanced in
the vasculature of the patient so that the second filling structure is
delivered to the aneurysm and the second filling structure is filled with
a second fluid filling medium so that an outer wall of the second filling
structure conforms to an inside surface of the aneurysm and an inner wall
of the second filling structure forms a second substantially tubular
lumen to provide a second blood flow path across the aneurysm. The second
scaffold is radially expanded from a contracted configuration to an
expanded configuration wherein in the expanded configuration the second
scaffold engages the inner wall of the second filling structure. The
second fluid filling medium may be hardened in the second filling
structure and the second flexible shaft is released from the second
filling structure. The second shaft may be retracted away from the second
filling structure.

[0051] The first filling structure may comprise a filling tube that is
fluidly coupled therewith and the step of filling the first filling
structure may comprise passing filling medium through the filling tube.
The filling tube may comprise an inner tube that is slidably disposed
therein and that is also fluidly coupled with the filling structure. The
method may further comprise removing the inner tube from the filling tube
and supplying additional filling medium to the filling structure by
passing the filling medium through the filing tube after the inner tube
has been removed therefrom.

[0052] These and other embodiments are described in further detail in the
following description related to the appended drawing figures.

[0054] FIG. 2 illustrates a delivery catheter carrying a single prosthesis
system which comprises a filling structure mounted over a scaffold
structure.

[0055] FIG. 3 illustrates a system comprising a pair of prostheses for
delivery to an infrarenal abdominal aortic aneurysm, where each
prosthesis comprises a delivery catheter carrying a filling structure
mounted over a scaffold structure.

[0056] FIGS. 4A-4I illustrate exemplary usage of the system in FIG. 3 for
treating an infrarenal abdominal aortic aneurysm.

[0057] FIG. 5 illustrates an aneurysm treatment system having a filling
structure and scaffold concentric with a delivery catheter.

[0058] FIG. 6 illustrates an aneurysm treatment system wherein the filling
structure is separate from the scaffold.

[0059] FIG. 7 shows an aneurysm treatment system having a filling
structure axially separated from the scaffold.

[0060] FIG. 8 illustrates an aneurysm treatment system similar to that of
FIG. 7, but with the relative positions of the filling structure and
scaffold reversed.

[0061] FIG. 9 illustrates an aneurysm treatment system having a filling
structure axially separated from the radially expandable balloon.

[0062] FIGS. 10A-10B illustrate the use of various sheath embodiments.

[0063] FIGS. 11A-11B show the use of a tether line to help guide movement
of the filling structure relative to the scaffold.

[0064] FIGS. 12A-12B show the use of a tether line to help pull the
filling structure toward the scaffold.

[0065] FIGS. 13A-13D illustrate the use of pressure monitoring to
facilitate filling of the filling structure.

[0066] FIG. 14A-14C illustrate the use of a pressure relief valve and
overflow reservoir.

[0067] FIGS. 15A-15B illustrate use of another pressure indicator
mechanism.

[0068] FIGS. 16A-16B illustrate pressure monitoring in the space between
the filling structure and the aneurysm wall.

[0069] FIGS. 17A-17C show a balloon catheter having various pressure
monitoring devices.

[0104] FIG. 1 illustrates the anatomy of an infrarenal abdominal aortic
aneurysm comprising the thoracic aorta (TA) having renal arteries (RA) at
an end above the iliac arteries (IA). The abdominal aortic aneurysm (AAA)
typically forms between the renal arteries (RA) and the iliac arteries
(IA) and may have regions of mural thrombus (T) over portions of its
inner surface (S).

[0105] Referring now to FIG. 2, a system 10 constructed in accordance with
the principles of the present invention for delivering a double-walled
filling structure 12 (also referred to as an endograft in this
disclosure) to an aneurysm includes the filling structure 12 disposed
over a radially expandable endoframe 27 (also referred to as a scaffold,
stent or scaffolding in this disclosure), both of which are then mounted
on a delivery catheter 14 having an expandable element 16, typically an
inflatable balloon, at its distal end. Expandable element 16 traverses
the entire length of the endoframe 27 so that the endoframe 27 may be
radially expanded upon expansion of the expandable element 16. Endoframe
27 traverses the entire length of filling structure 12 and most of
endoframe 27 is covered by filling structure 12, however endoframe 27
also has proximal and a distal regions that extend uncovered beyond the
filling structure 12. One of skill in the art will appreciate that
lengths of the filling structure, endoframe and expandable element may be
adjusted as required and thus the relative lengths are not limited to
those disclosed above. Further details about the double-walled filling
structure are disclosed in U.S. Patent Publication No. 2006/0212112
(Attorney Docket No. 025925-001610US) and preferred embodiments of an
endoframe scaffold are disclosed in U.S. Provisional Patent Application
No. 61/029,225 (Attorney Docket No. 025925-002710US) and U.S. patent
application Ser. No. 12/371,087 (Attorney Docket No. 025925-002720US),
both of which the entire contents are incorporated herein by reference.
The catheter 14 will comprise a guidewire lumen 18, a balloon inflation
lumen (not illustrated) or other structure for expanding other expandable
components, and a filling tube 20 for delivering a filling medium or
material to an internal space 22 of the double-walled filling structure
12. The internal space 22 is defined between an outer wall 24 and inner
wall 26 of the filling structure. Upon inflation with the filling
material or medium, the outer wall 24 will expand radially outwardly, as
shown in broken line, as will the inner wall 26, also shown in broken
line. Expansion of the inner wall 26 defines an internal lumen 28. The
expandable balloon or other structure 16 will be expandable to
correspondingly expand the endoframe 27 to provide support and to shape
an inner surface of the lumen 28. In this embodiment, the expandable
balloon is substantially cylindrically shaped and therefore the lumen
will also be cylindrically shaped. In other embodiments, the balloon may
be pre-shaped to more precisely match the curvature of the vessel. For
example, when treating an aortic aneurysm, a tapered, pre-shaped or
curved balloon may be used so that the lumen substantially matches the
aorta. Various balloon configurations may be used in order to match
vessel tortuosity. Pre-shaped, curved or tapered balloons may be used in
any of the embodiments disclosed herein in order to obtain a desired
lumen shaped.

[0106] In a particular and preferred aspect of the present invention, a
pair of double-walled filling structures will be used to treat infrarenal
abdominal aortic aneurysms, instead of only a single filling structure as
illustrated in FIG. 1. A system comprising such a pair of filling
structures is illustrated in FIG. 3 which includes a first filling
structure 112 and a second filling structure 212. Each of the filling
structures 112 and 212 are mounted on delivery catheters 114 and 214,
respectively and each system also has a radially expandable endoframe
scaffold 127, 227. The components of the filling structures 112 and 212,
the endoframes 127, 227 and delivery catheters 114 and 214 are generally
the same as those described previously with respect to the single filling
structure system 10 of FIG. 1. Corresponding parts of each of the filling
systems 112 and 212 will be given identical numbers with either the 100
base number or 200 base number. The filling structures 112 and 212 will
generally be positioned adjacent each other within the aneurismal space
to fill that space, as will be described with specific reference to FIGS.
4A-4I below.

[0107] FIGS. 4A-4I illustrate an exemplary use of the system in FIG. 3 for
treating an infrarenal abdominal aortic aneurysm AAA with or without
mural thrombus T. An optional sheath may be disposed over the scaffold
and/or filling structure as seen in FIG. 10A. In FIG. 4A a pair of
guidewires (GW) will first be introduced preferably percutaneously or by
surgical cut down, from each of the iliac arteries (IA) and advanced
across the aneurysm toward the renal arteries (RA). Referring now to FIG.
4B, the first delivery catheter 114 having expandable balloon 116 will
then be positioned over one of the guidewires GW to position the
double-walled filling structure 112 across the aortic aneurysm (AAA)
along with scaffold 127. The second delivery catheter 214 having
expandable balloon 216 is then delivered over the other guidewire GW to
position the second filling structure 212 adjacent to the first structure
112 across the aneurysm (AAA) along with scaffold 227, as illustrated in
FIG. 4C. If either of the delivery catheters 114, 214 include sheaths
covering their respective scaffold and/or filling structure, the sheath
(not illustrated) will be retracted. Typically, one of the filling
structures 112, 212 and associated balloons 116, 216 will be expanded
first along with the corresponding scaffold 127, 227, followed by the
other filling structure, scaffold and balloon. In some embodiments, both
balloons may be radially expanded simultaneously thereby also expanding
the filling structures and scaffolds simultaneously.

[0108] Alternatively, one or both filling structures 112, 212 may be
filled with a hardenable material and then the filling structures 112,
212 are radially expanded along with the corresponding scaffold 127, 227.
In still other embodiments, combinations of filling and expanding may be
performed in different order depending on physician preference and
aneurysm anatomy. In some embodiments, an optional unfurling of the
filling structure may be performed prior its filling and radial
expansion. In this optional step, once the delivery system is positioned
across the aneurysm, the filling structure may be filled with CO2
gas, contrast media, saline or other fluids to unfurl the filling
structure away from the delivery catheter thereby helping to ensure more
uniform filling later on. During unfurling, the filling structure may be
partially filled or fully filled so that it conforms to the inner
aneurysm wall. Once unfurled, the fluid may be removed from the filling
structure and it may be filled with the hardenable material to expand and
conform to the aneurismal space between the lumens and the inner aneurysm
wall. Pressure relief valves such as those described below may also be
used to ensure that the filling structure is not over filled.

[0109] In another variation of the method, an optional contrast
pre-filling step may be utilized. In this embodiment, after the delivery
catheter is positioned across the aneurysm and the endoframe has been
radially expanded, the filling structure may be pre-filled with contrast
media so as to permit observation of the filled filling structure under a
fluoroscope relative to the aneurismal sac. Additionally, the pre-filling
step allows the physician to record the pressure and volume of the
contrast media used for optimal filling of the filling structure and this
will provide an estimate of volume and pressure to be used when filling
the filling structure with the hardenable filling material. In order to
prevent overfilling of the filling structure, any of the pressure relief
valves disclosed below may also be used to bleed off excess fluid from
the filling structure.

[0110] FIG. 4D illustrates inflation of balloon 116 along with scaffold
127 in addition to expansion and filling of filling structure 112. The
filling structure 112 and balloon 116 are expanded and inflated to fill
generally half of the aneurismal volume, as illustrated in FIG. 4D.
Filling and expansion can generally be carried out as described in U.S.
Patent Publication No. 2006/0212112 (Attorney Docket No. 025925-001610US)
for one filling structure, except of course that the filling structure
112 will be expanded to occupy only about one-half of the aneurismal
volume. U.S. Patent Publication No. 2006/0212112 discloses filling of one
filling structure in more detail including pressures, filling materials
and other details, the entire contents of which have previously been
incorporated herein by reference. After the first filling structure 112
has been filled, the second filling structure 212 may be filled and
expanded along with scaffold 227, as illustrated in FIG. 4E. FIG. 4E also
illustrates a cut away view of the expanded scaffolds 127, 227 within the
filled filling structures 112, 212. The upper ends of the balloons 116
and 216 will conform the tubular lumens of the filling structures against
the walls of the aorta as well as against each other, while the lower
ends of the balloons 116 and 216 will conform the tubular lumens into the
respective iliac artery, IA. The expanded scaffold 127 not only provides
support to filling structure 112, but also creates and shapes a lumen for
blood passage from the aorta to one of the iliac arteries. Similarly,
expanded scaffold 227 also provides a lumen for blood passage from the
aorta into the other iliac artery. In some protocols filling of the
filling structures (either both filled simultaneously or one after the
other) may be performed before, during or after radial expansion of the
balloons and the scaffolding 127, 227 (either both expanded
simultaneously or one after the other). Additionally, as discussed above
with respect to FIG. 2, the scaffolds 127, 227 may be radially expanded
using a cylindrically shaped balloon to form a substantially
cylindrically shaped lumen. Curved, tapered or pre-shaped balloons may
also be used to expand the scaffolds 127, 227, thereby forming a lumen
that also is curved, tapered or shaped. The curved, tapered or pre-shaped
balloon may be selected to match the anatomy of the vessel in which the
scaffold and endograft is placed. Pre-shaped, curved or tapered balloons
may be used in any of the other embodiments disclosed herein in order to
obtain a desired lumen shape.

[0111] After filling the filling structures 112 and 212 as illustrated in
FIG. 4E, the filling materials or medium will be cured or otherwise
hardened as described in U.S. Patent Publication No. 2006/0212112 and the
delivery catheters 114 and 214 removed, respectively. The hardened
filling structures along with the expanded scaffolds 127, 227 will then
provide a pair of tubular lumens opening from the aorta beneath the renal
arteries to the right and left iliac arteries, as shown more clearly in
broken line in FIG. 4F. The ability of the filling structures 112 and 212
to conform to the inner surface (S) of the aneurysm, as shown in FIG. 4F,
helps the structures to remain immobilized within the aneurysm with
little or no migration. Immobilization of the filling structures 112 and
212 may be further enhanced by providing any of the surface features
described in U.S. Patent Publication No. 2006/0212112 which has been
incorporated herein by reference.

[0112] The double filling structure embodiments will include at least one
separate scaffold deployed within each of the tubular blood flow lumens.
The scaffolds will generally be endoskeletal structures that lay the
foundation for new lumens, and will be deployed within the tubular lumens
of the double-walled filling structures using balloon or other expansion
catheters (in the case of malleable or balloon-expandable scaffolds) and
an optional retractable constraining sheath. FIG. 4G more clearly shows
the first scaffold 127 disposed within the tubular lumen of the first
filling structure 112 while a second scaffold 227 is disposed in the
tubular lumen of the second filling structure 212. As illustrated, in
this exemplary embodiment, the scaffolds are balloon expandable
structures which extend into the iliac arteries IA at the lower end of
the filling structures. In other embodiments, the scaffolds may be
self-expanding stent-like structures fabricated from a shape memory alloy
such as Nitinol.

[0113] Referring now to FIG. 4H, first and second scaffolds 127 and 227
may extend upwardly on the aortic side of the first and second filling
structures 112 and 212. When the scaffold structures extend into the
thoracic aorta TA, it will usually be desirable that they be expanded so
that they conform to each other along a plane or region of contact. For
example, as shown in FIG. 4I, the upper ends of the scaffolds 127, 227
may be formed preferentially to have D-shaped cross-sections when
expanded, although other cross-sections such as elliptical, circular,
etc. may be formed. Thus, flat faces 258 and 260 will engage each other
with the remaining portion of the stent conforming to the inner wall of
the aorta. In this way, most of the cross-sectional area of the aorta
will be covered with the scaffold, thus enhancing blood flow through the
filling structures. Other configurations are disclosed in U.S. Patent
Publication No. 2006/0212112 previously incorporated herein by reference.

[0114] In the exemplary embodiment of FIGS. 4A-4I, the scaffold and
filling structure are both disposed coaxially and generally
concentrically over an expandable member coupled to a delivery catheter
and the entire system is delivered to the aneurysm at one time. FIG. 5
shows a similar coaxial and concentric system 300 for treating aneurysms
where a filling structure 308, also referred to as an endograft is
coaxially disposed over stent-like scaffold 306, both of which are then
coaxially and concentrically positioned over a radially expandable
balloon 304 which is coupled to the distal region of a catheter shaft
302. Proximal and distal portions of scaffold 306 extend uncovered by
filling structure 308 and a filling tube 310 allows a fluid to be
delivered to the filling structure 308. While this embodiment is
promising, in certain situations, the filling structure may move relative
to the endoframe during delivery, thereby resulting in inaccurate
placement of one or both devices. It would therefore be advantageous to
provide a more effective way of coupling the filling structure with the
endoframe to minimize such movement and to facilitate more accurate
delivery of the scaffold and endograft to the treatment site. FIG. 29
illustrates an exemplary embodiment that employs a releasable coupling
mechanism to help minimize such movement. In FIG. 29, the distal region
of a delivery catheter having a filling structure and an endoframe
disposed thereover is highlighted. Filling structure 2902 is disposed
over an endoframe 2904, both of which are also disposed over a radially
expandable balloon 2906 coupled to catheter shaft 2908. The distal end of
catheter shaft 2908 includes an atraumatic tapered nosecone 2910 having a
receiving aperture 2920. The releasable coupling mechanism includes a
lockwire 2918 that runs substantially parallel with catheter shaft 2908,
with the distal end of the lockwire 2918 disposed in the receiving
aperture 2920 in nosecone 2910. The releasable coupling mechanism also
uses a tether 2914. Tether 2914 is releasably coupled with the lockwire
2918, the filling structure 2912 and the catheter shaft 2908, thereby
minimizing relative motion of the endoframe 2904 to the filling structure
2902 during delivery. The tether may be a thin wire fabricated from metal
or a polymer or it may be a suture or other filament-like material.
Coupling is accomplished by passing one end of the tether 2914 through a
tether loop 2912 attached to the filling structure 2902 and one end of
the tether is then releasably coupled with the lockwire 2918 using a
releasable knot, here a constrictor knot 2916. Constrictor knots are well
known in the art and may be seen in greater detail in FIGS. 30A-30B. The
opposite end of the tether is secured to the distal region of the
delivery catheter 2922 with a knot such as a constrictor knot, or bonded,
welded or otherwise fixed to the catheter shaft. This configuration helps
keep the filling structure 2902 from moving relative to the endoframe
2904 and the delivery catheter 2908 during delivery. FIG. 29 illustrates
a single tether coupled with a single tether loop. Using the
tether/pullwire coupling system, movement of the filling structure
relative to the endoframe is limited to ±5 mm preferably, and more
preferably to ±3 mm and the endoframe/filling structure can be
positioned in the aneurysm to within ±7 mm of a target implantation
site, and more preferably to within ±5 mm of the target site.

[0115] In use, once the filling structure 2902 and the endoframe 2904 have
been delivered to a desired position, the lockwire 2918 may be retracted
proximally so that its distal tip disengages from aperture 2920 and the
lockwire is removed from under the constrictor knot 2916 allowing the
knot to unfurl. This de-couples the endoframe 2902 from the delivery
catheter 2908 so that the two may be separated from one another. One end
of the tether remains coupled with the catheter so that the tether may
also be removed from the body.

[0116] The embodiment of FIG. 29 only illustrates a single tether. In
other embodiments, multiple releasable coupling mechanisms using tethers
may be coupled with multiple tether loops. For example, two, three, four
or more releasable coupling mechanisms having two, three, four or more
tethers may be disposed circumferentially and optionally symmetrically
around the catheter and filling structure coupled with a matching number
of tether loops coupled with the filling structure. In other embodiments,
one, two, three, four, or more releasable coupling mechanisms using
tethers may be coupled to both the proximal and distal ends of the
filling structure with tether loops on the proximal and distal ends of
the filling structure. FIG. 31 illustrates an exemplary embodiment of a
device having two releasable coupling mechanisms including tethers. In
FIG. 31 a delivery sheath 3102 is disposed over the endoframe 3118 and
filling structure 3104 during delivery to the aneurysm, typically over a
guidewire GW. Once delivered to the aneurysm, the endoframe 3118 and the
filling structure 3104 are advanced and exposed from the delivery sheath
3102 (or the delivery sheath is retracted). Two releasable coupling
mechanisms having two tethers 3110 and 3128 are used to help couple the
filling structure 3104 with the endoframe 3118. A first tether 3110
passes through a tether loop 3122 attached to the filling structure 3104
while one end of the tether is releasably connected to the lockwire 3108
using a knot 3124 such as the constrictor knot previously disclosed
above. The other end 3114 of the tether 3110 is coupled with a distal
portion of delivery catheter 3116 or nose cone 3106. A second tether 3128
passes over the lockwire 3108 and through a second tether loop 3126
attached to the other end of the filling structure 3104. The second
tether 3128 is then releasably coupled with the fill tube 3132 extending
from the filling structure 3104 using a knot 3130 such as a constrictor
knot. The fill tube 3132 allows the filling structure 3104 to be filled
with hardenable medium from outside the patient's body. The lockwire 3108
runs substantially parallel with the delivery sheath 3102 and is disposed
under the filling structure 3104. The distal end of the lockwire 3108 is
releasably received in an aperture 3112 in tapered nosecone 3106 and the
proximal end may be manipulated by the physician from outside the
patient's body. In addition to helping prevent movement of the filling
structure relative to the scaffold, the second tether 3128 helps to
prevent release of the fill tube 3132 from the filing structure 3104,
thus providing a fail safe mechanism prior to filling, and during filling
or re-filling of the filling structure and until the procedure is over
and it is desired to separate the filling tube from the filling
structure. Endoframe 3118 is crimped over balloon 3120 which is coupled
with the delivery catheter shaft 3116. In these exemplary embodiments, a
tether is used in the releasable coupling mechanism to prevent unwanted
movement of the filling structure relative to the scaffold. One of skill
in the art will appreciate that other releasable coupling mechanisms may
be used and therefore the coupling mechanism is not limited to tether
embodiments. Additionally, the tether may be used as a releasable
coupling mechanism in any of the embodiments disclosed in this
specification.

[0117] The coupling mechanism described in FIG. 31 also allows positioning
of the filling structure relative to the endoframe by movement of the
delivery catheter, as illustrated in FIGS. 32A-32B. In FIG. 32A,
depending on how taut the tethers 3110 and 3128 are, the delivery
catheter 3116 may be advanced or retracted as indicated by the arrows to
position the endoframe 3118 and delivery catheter 3116 relative to the
filling structure 3104. Similarly, in FIG. 32B, the delivery catheter
3116 may be advanced into the filling structure 3104 or retracted away
from the filling structure 3104 as indicated by the arrows. This
embodiment may be used when in situ adjustment is desired or during
"serial deployment" where either the filling structure or the endoframe
is deployed before the other and then the two components are aligned in
the aneurysm, as will be discussed in greater detail below. In addition
to serial delivery of a scaffold and endograft, the releasable coupling
mechanisms described herein (e.g. the tether embodiments described above)
may also be used in parallel delivery of the two components as will be
discussed in greater detail below. Thus, releasable coupling mechanisms
such as tethers may be used in any of the embodiments disclosed herein.
Sometimes, the lockwire will be covered with a support post. In FIG. 35,
a loop 3514 coupled with the filling structure 3502 is fed into an
aperture 3516 of a support post 3512. A lockwire 3510 is fed through the
support post 3512 and through the loop 3514, thereby coupling the filling
structure 3502 with the lockwire 3510. The distal end of the lockwire
3510 is received in an aperture 3508 on nosecone 3506 of the delivery
catheter 3504. This configuration prevents the support post from having a
free end that could extend and cause damage or trauma to the vasculature.
Retraction of the lockwire 3510 past the aperture 3516 releases the loop
3514 from the lockwire 3510.

[0118] In other embodiments, the filling structure may be coupled more
directly with the endoframe. For example, in FIG. 33, the endoframe 3304
includes eyelets 3306 near it's proximal and distal ends. Tether loops
3308 may then be looped through the eyelets 3306 and secured to the
filling structure 3302. This way, the filling structure 3302 will be
fixed relative to the endoframe as long as the tether loops are taut.
Generally, this coupling mechanism will allow about ±5 mm and more
preferably ±3 mm of relative movement between the filling structure
and the endoframe. Also, the filling structure and endoframe should be
positionable within ±7 mm and more preferably between ±5 mm of a
target position within the aneurysm of the filling structure 3302.

[0119] In place of tethers coupled with the filling tube (such as tether
3128 in FIGS. 32A-32B), spring loaded arms may be used. In FIG. 34,
filling structure 3402 includes a filling tube 3410 for filling the
filling structure with hardenable medium. A pair of spring arms 3414 are
coupled with the filling tube 3410 at one end, and the opposite ends of
the arms 3414 are coupled with the filling structure 3402. The ends are
wrapped around a loop 3412 coupled with the filling structure 3402. In
this embodiment, the arms are wire-like elements made from spring temper
metal such as stainless steel or superelastic nitinol, although other
materials could be used such as a resilient polymer. Since the filling
structure is coupled with the filling tube, they are fixed to one another
and relative movement is not possible. The arms 3414 are advantageous
since upon deployment from a constraining sheath (not illustrated), the
arms radially expand outward, facilitating opening of the filling
structure so it is may receive the delivery catheter 3406 having an
endoframe 3404 mounted over a balloon 3408. Again, this embodiment may be
used when the filling structure and the endoframe are delivered
separately, as discussed below.

[0120] In addition to the potential challenge of minimizing movement of
the endoframe relative to the filling structure, the embodiment described
in FIG. 5 may present other challenges. For example, because of the
stackup of multiple elements on top of one another, the distal region of
system 300 has a relatively large profile which can make it difficult to
insert percutaneously into the patient's vasculature and in some cases
(e.g. through tortuous vessels or through stenotic regions) it also is
difficult to advance to the aneurysm. Therefore, other delivery system
configurations are possible which may help reduce profile and facilitate
delivery. These delivery systems have an outer diameter preferably
ranging from 10 French to 18 French, and more preferably have an outer
diameter ranging from 12 French to 16 French.

[0121] FIG. 6 illustrates an alternative embodiment where the system 320
utilizes independent delivery of the filling structure and the scaffold.
In FIG. 6, a filling structure 326 is disposed over a balloon 324 which
is coupled to a first delivery catheter 322. A filling tube 328 allows
the filling structure 326 to be filled with a hardenable material. A
second delivery catheter 330 carries a second balloon 332 having a
scaffold 334 disposed thereon. In this embodiment, the endograft may be
delivered to the aneurysm first where it is expanded and filled via
filling tube 328 and then the first catheter 322 is removed from the
filling structure 326. The second catheter 332 is then advanced into the
lumen created by the filling structure 326 and then balloon 332 is
expanded thereby correspondingly expanding scaffold 334 within filling
structure 326. Alternatively, after filling structure 326 has been
expanded and filled, delivery catheter 322 may be removed from the
patient's body and scaffold 334 may be mounted on the same delivery
catheter 322 for delivery and expansion into the filling structure 326.
This alternative embodiment provides some advantages over the embodiment
of FIG. 5 such as having a lower profile but still has challenges such as
the increased cost and waste associated with using two separate delivery
catheters or an increased procedure time to deliver and deploy the
filling structure and scaffold independently of one another. One possible
solution is to provide a delivery catheter having two independently
expandable balloons disposed on a delivery catheter. The balloons are
separated from one another by a predetermined distance. A scaffold is
placed over one balloon and an endograft is placed over the second
balloon. Thus, a single catheter may be used to deliver both the graft
and scaffold to the aneurysm where the graft and scaffold are then
independently deployed into the aneurysm.

[0122] Another embodiment which reduces the need for two delivery
catheters and also reduces procedure time by eliminating the need to
remove the catheter from the patient and then mount a scaffold thereover
is illustrated in FIG. 7. In FIG. 7, a single delivery catheter carries
both scaffold and filling structure to the aneurysm while still providing
a system with reduced delivery profile. Delivery system 350 includes a
delivery catheter 352 having an expandable balloon 358. Scaffold 360 is
mounted directly over the balloon 358 and the filling structure 354 is
positioned distal to the scaffold 360 such that the two implants are
axially separated from one another and a gap or spacing 362 separates
them. The releasable coupling mechanisms described above, including the
tether embodiments may be used to limit movement between the scaffold and
the filling structure. The delivery catheter 352 may be advanced to the
aneurismal treatment site such that filling structure 354 traverses the
aneurysm. The filling structure 354 may be filled via filling tube 356 so
that it conforms to the aneurysm and then scaffold 360 may be advanced
distally in the direction of arrow 364 so that is received in the lumen
of filling structure 354. Balloon 358 may then be radially expanded so as
to expand scaffold 360 into the inner wall of filling structure 354. In
an alternative embodiment, after filling structure 354 is positioned
across the aneurysm, scaffold 360 may be advanced into the lumen of
filling structure 354. Both are then radially expanded by expansion of
balloon 358 and the filling structure is filled either before, during or
after radial expansion. System 370 of FIG. 8 is similar to that of system
350 in FIG. 7 except that the relative positions of the scaffold 360 and
filling structure 354 have been reversed. This time, in the embodiment of
FIG. 8, scaffold 360 is retracted proximally in the direction of arrow
366 into the lumen of filling structure 354. One of ordinary skill in the
art will appreciate the motion of the components is relative, thus
instead of advancing a first component into a second component, the
second component may be retracted over the first component. Similarly,
retraction of a first component into a second component may also be
achieved by advancing the second component over the first component.

[0123] Yet another embodiment that helps reduce delivery profile is
illustrated by system 390 in FIG. 9. In FIG. 9, a filling structure 392
having filling tube 398 is disposed over delivery catheter 396 and
axially separated from radially expandable balloon 394 by a spacing 399.
In this embodiment, the filling structure 392 may be delivered to the
aneurysm where it is filled and balloon 394 is expanded to help form the
lumen in filling structure 392. Alternatively, the filling structure may
be retracted over balloon 394 either before, during or after delivery to
the aneurismal treatment site and then it may be expanded and filled. A
separate scaffold (not illustrated) may then be delivered and deployed in
the lumen created by the inner wall of filling structure 392. A
releasable coupling mechanism, such as the tether embodiments previously
described above may also be included in this embodiment to minimize
movement of the filling structure relative to the scaffold.

[0124] Some delivery systems may include a sheath. Any of the embodiments
previously described may include a sheath in order to protect the
scaffolding and/or the filling structure. In some embodiments where the
scaffolding is self-expanding, the sheath acts as a constraint to keep
the scaffolding from self-expanding. FIG. 10A illustrates a delivery
system having a balloon 406 disposed over a catheter shaft 404. A balloon
expandable scaffolding 408 is disposed over the balloon 406 and a filling
structure 410 is also disposed over the catheter shaft 404 axially
separated from the balloon 406. An outer sheath 402 is disposed over both
the scaffolding 408 and the filling structure 410. Moving the sheath 402
away from the scaffolding 408 exposes the scaffolding 408 and/or filling
structure 410 so that either may be radially expanded by balloon 406 or
allows expansion of filling structure 410 due to filling. FIG. 10A also
illustrates an optional pusher tube 412 having a distal end that can
engage the proximal end of the endograft. The pusher tube keeps the
endograft from moving as the outer sheath 402 is retracted and also helps
to support the endograft and prevent it from collapsing during sheath
retraction. The pusher tube 412 and the sheath 402 may be extruded using
manufacturing techniques well known to those of ordinary skill in the art
and may be fabricated from a number of polymers such as polyethylene,
polyurethane, Teflon, PVC, nylon and the like.

[0125] FIG. 10B illustrates another sheath embodiment similar to the
embodiment of FIG. 10A, except in this embodiment the sheath has a
tapered distal end. Because the balloon 406 and scaffolding 408 are
distal relative to the filling structure 410 and because of the larger
profile of the endograft filling structure 410 relative to the
scaffolding 408, a step exists between the filling structure 410 and the
scaffolding 408. Tapered region 403 in sheath 402 provides a smoother
transition between these two regions. In order to facilitate retraction
of the sheath over the filling structure 410, the tapered tip 403 may be
perforated or longitudinally slit. Thus, as sheath 402 is retracted and
as the tapered region 403 begins to engage filling structure 410, the
slits or perforations will open up allowing the smaller diameter sheath
tip to pass over the filling structure 410. In a preferred embodiment,
two slits approximately 180 degrees apart may be imparted into the sheath
tip, although it will be recognized that additional slits or even a
single slit may be used.

[0126] Other variations on the orientation of the balloon, filling
structure and scaffolding may also be employed. For example, in some
embodiments the endoframe scaffolding and filling structure may be
mounted coaxially over a catheter shaft either proximal of or distal to a
balloon. The scaffolding and filling structure are positioned at the
treatment site and then the balloon is positioned within the scaffolding
and filling structure and expanded. In a variation of this embodiment, a
thin split tubular liner may be positioned over the balloon and passes
through the inner diameter of the filling structure. The thin liner acts
as a guide for the balloon during use. Thus, as the balloon is axially
positioned within the scaffolding and filling structure, the thin liner
guides the balloon through the inner diameter of the scaffolding. When
the balloon is expanded, the thin liner splits along perforations or slit
regions to allow radial expansion thereof.

[0127] For example, in FIGS. 36A-36B, a smooth sheath or covering 3608 may
be disposed over all or a portion of the endoframe 3606 and balloon 3610.
This is useful in embodiments where the endoframe 3606 and catheter shaft
3604 are advanced into the filling structure 3602 (e.g. FIG. 7) or where
the endoframe 3606 and catheter shaft 3604 are retracted into the filling
structure (e.g. FIG. 8). Covering all or a portion of the balloon 3610
and endoframe 3606 allows both to easily be received into the filling
structure 3602 without binding or damaging either component. When the
balloon is inflated, the cover 3608 will be pushed away from and off the
endoframe 3606 and balloon 3610, allowing full expansion as seen in FIG.
36B.

[0128] FIG. 37 illustrates another embodiment using a sheath or cover. In
FIG. 37, the entire endoframe 3704 and balloon 3708 are covered by the
sheath 3702 to facilitate smooth entry of the endoframe 3704 into the
filling structure 3706 when the catheter shaft 3710 is moved in the
direction of the arrow. FIG. 38 illustrates still another embodiment
using a sheath. In FIG. 38, a sheath or sleeve 3802 not only covers the
endoframe 3804 and balloon 3808, but extends all the way through the
filling structure 3810. Thus, when the delivery catheter 3806 is
advanced, the endoframe 3804 easily slides through the sleeve 3802 and
avoids rubbing against the inner wall of the filling structure 3810. The
sleeve 3802 may then be easily retracted and removed prior to deployment
of the endoframe and filling structure.

[0129] A split sheath or a perforated sheath may also be used to
facilitate deployment of the device. For example, FIG. 52A illustrates a
filling structure 5210 having a filling tube 5214 disposed over a
scaffold 5212 which is carried by a balloon 5208 on a delivery catheter
shaft 5206 having a distal nosecone 5204. The delivery catheter is
delivered over a guidewire GW and covered with a sheath 5202 during
delivery. Upon deployment, the sheath 5202 is retracted and the filling
structure 5210 is filled and endoframe 5212 is expanded with balloon
5208. The delivery catheter 5206 is then retracted away from the expanded
endoframe 5212 and expanded filling structure 5210 as seen in FIG. 52B.
In some situations, the physician may desire to further expand the
endoframe 5212 with a larger size balloon. This requires that the
delivery catheter 5206 be removed and replaced. However, the nosecone
5204 cannot be retracted into the sheath 5202 due to interference with
the filling tube 5214. A tapered split sheath or a tapered perforated
sheath may be used to overcome this challenge. FIG. 52C illustrates a
tapered split sheath 5216. The tapered split sheath 5216 allows for a
smaller nosecone 5204, which can pass through the sheath. Because the
sheath 5216 is tapered at the tip, it must split to pass over the filling
structure 5210. This allows the delivery catheter to be retracted from
the patient and replaced with a different catheter having a different
balloon size for post-dilation of the endoframe.

[0130] In other embodiments, a tether line may be used to help guide
movement of the filling structure relative to the scaffolding. FIGS.
11A-11B illustrate the use of such a tether line. In FIG. 11A, a delivery
system 420 includes an elongate flexible shaft 422 having a balloon 430
disposed near the distal end of the shaft 422. A stent-like scaffolding
432 is carried by the balloon 430. A filling structure 436 with filling
tube 438 is also disposed over shaft 422. Filling structure 436 has four
eyelets 434 which serve as guides for tether lines 428 to pass through.
Tether lines 428 extend from the proximal end of delivery system 420,
through eyelets 434 and are coupled to nosecone 426. Nosecone 426 is
coupled to shaft 424 which is movable relative to shaft 422. Shaft 422 is
retracted over shaft 424 such that balloon 430 and scaffold 432 are
slidably received by filling structure 436. FIG. 11B shows retraction of
scaffolding 432 into filling structure 436 with a longer length of shaft
424 exposed. Tether lines 428 help guide the filling structure 436 so
that it mates with scaffolding 432 and is retracted into the filling
structure 432. In this exemplary embodiment, four eyelets 434 are used,
although more or less may also be used. The eyelets 434 may be integral
with the filling structure 436 or they may be separate components bonded
or otherwise attached thereto. Once the scaffolding has been retracted
into a desired position within filling structure 436, the tether lines
428 may be pulled from nosecone 426 and away from the filling structure
436 so that it may be expanded and filled in the aneurysm.

[0131] FIGS. 12A-12B illustrate an alternative embodiment of a system 450
employing tether lines. In FIGS. 12A-12B, tether lines are used to pull
the filling structure toward the scaffolding so that the two components
are properly aligned. In FIG. 12A, a catheter shaft 456 carries a balloon
460 disposed near the shaft's distal end and a scaffolding 462 is
disposed over the balloon. A nosecone 454 is coupled to the distal end of
shaft 456 and a filling structure 452 having a filling tube 464 is
disposed over the catheter shaft adjacent the balloon 460 and scaffold
462. The nosecone has a taper 457 on the proximal end as well as an
optional taper on the distal end, that way the nosecone helps guide the
catheter as it is being advanced through the vasculature and the proximal
taper helps the catheter pass through the filling structure as the
catheter is being retracted away from the filling structure. Tether lines
458 are removably coupled to filling structure 452 and extend distally to
nosecone 454. Tether lines 458 extend through nosecone 454 and then
extend proximally through a lumen in shaft 456 (not shown) until the
tether lines 458 exit the proximal end of the catheter shaft 456. As the
proximal portion of tether lines 458 are pulled proximally away from the
aneurysm, filling structure 452 is advanced until it is properly
positioned over the scaffolding 462 and balloon 460. The tether lines may
then be pulled free from filling structure 452 and pulled into nosecone
454 as seen in FIG. 12B. The filling structure 452 and scaffold 462 may
then be filled and expanded into the aneurysm. In an alternative
embodiment, the shaft 456 and scaffolding 462 may be retracted into
filling structure 452.

[0132] A hitch may also be used to move the filling structure relative to
the scaffolding. FIGS. 22A-22B illustrate an exemplary embodiment of a
hitch. In FIG. 22A eyelet or suture loop 702 is coupled with a filling
structure 712 (FIG. 22B). Here, one loop is disclosed, although
additional suture loops may also be used. The suture loop 702 is used to
hitch the filling structure 712 with a hypotube 760 so that the filling
structure may be advanced. Hypotube 706 runs substantially parallel with
the delivery catheter shaft (not illustrated here). A distal portion of
the hypotube 706 is skived 708 to create a receptacle for receiving the
suture loop 702. A lockwire 704 passes through the hypotube 706 and
through the suture loop 702, thereby locking the suture loop 702 to the
hypotube 706. When the hypotube 706 is advanced distally suture loop 702
is tensioned and thus, the filling structure may be advanced distally
over the scaffolding 710. Once the filling structure 712 is placed in the
desired position relative to scaffolding 710, the lockwire 704 may be
refracted proximally from the hypotube 706 releasing the suture loop 702
from the skived region 708. The hypotube 706 and lockwire 704 may then be
retracted away from the filling structure 712 and removed from the
patient.

[0133] Sometimes, it may be desirable to increase the columnar strength of
the endograft in order to prevent it from buckling or otherwise
collapsing. Suturing the endograft to the scaffold may be used to help
keep the two structures coupled together. Some embodiments utilize wires
or metal frames in the filling structure or attached thereto in order to
provide additional support. A pocket or receptacle on the filling
structure may also provide enhanced column strength. FIGS. 23A-23C
illustrate an exemplary embodiment with a pocket.

[0134] In FIG. 23A, filling structure 730 comprises a pocket or receptacle
formed in a wall of the filling structure 730, near its distal end. The
pocket 734 may be made from the same material as the filling structure
730, or it may be another resilient material. The pocket 734 is generally
closed along three sides and has one end open, preferably proximally
oriented. The opening is sized to slidably receive a tensioning tube, rod
or hypotube 732. In use, the tensioning tube 732 is inserted into the
pocket 734 until it's distal end bottoms out. FIG. 23B shows the
tensioning tube 732 traversing the unrolled, flattened filling structure
730 substantially parallel to the longitudinal axis thereof. A filling
tab 736 is coupled with a proximal end of the filling structure 730 and a
filling tube 738 is fluidly connected to the filling tab 736. The filling
tube 738 extends proximally so that the filling structure 730 may be
filled from outside the patient's body. The filling tube 738 may be used
to apply tension to the proximal end of the filling structure 730 and
thus the filling structure 730 is captured between the pocket 734 on the
distal end of the filling structure 730 and the filling tube 738 on the
proximal end. In an alternative embodiment, the proximal end of the
filling structure 730 may utilize the hitch previously disclosed in FIGS.
22A-22B. FIG. 23C shows a pocket 734 on the distal end of filling
structure 730 and a suture loop 740 on the proximal end of filling
structure 730. Tensioning tube 732 is inserted into pocket 734 and also
uses the hitch of FIGS. 22A-22B to capture suture loop 740. In either
embodiment, once the filling structure is delivered to the treatment
site, filled and deployed, the tensioning tube 732 may be retracted from
the pocket 734 and the hitch released, thereby disengaging the tensioning
tube 732 from the filling structure 730.

[0135] Another exemplary embodiment of a filling structure and scaffolding
delivery system is seen in FIG. 24. In FIG. 24, a delivery catheter has a
nosecone 752 attached to a center shaft 758 via a tip 754 member. An
endograft filling structure 756 is positioned coaxially over the center
shaft 758. Also coaxial to the center shaft 758 and proximal to the
filling structure 756 is a sliding shaft 764 which can slide axially
along the center shaft 758. Attached distally to the sliding shaft 764 is
an expandable member 760, here a balloon, which has a stent-like
scaffolding 762 crimped thereover. Coaxial to both shafts 758, 764 is an
outer sheath 766 which has an inner diameter large enough to contain both
shafts 758, 764, the balloon 760, scaffolding 762 and filling structure
756. A pullwire 768 runs substantially parallel to the longitudinal axis
of the shafts 758, 764, outside of the balloon 760 and scaffolding 762
and through the inner diameter of the filling structure 756. The pullwire
768 is removably coupled to the filling structure 756 at two or more
positions. In use, the outer sheath 766 is retracted to expose the
filling structure 756. The balloon 760 and scaffolding 762 are advanced
over the center shaft 758 by advancing the sliding shaft 764, through the
inner diameter of the filling structure 756 until the balloon 760 and
scaffolding 762 are axially aligned with the filling structure 756. The
balloon 760 may then be inflated, radially expanding the scaffolding 762
within the filling structure 756. The filling structure 756 may then be
filled with a hardenable material and the pullwire 768 is retracted to
release the filling structure 756 from the shaft 758 and the delivery
catheter may then be removed from the patient.

[0136] Many of the filling structure embodiments include a filling tube.
FIG. 4IA illustrates an embodiment where a single lumen filling tube 4106
may extend from the filling structure 4102 proximally so that the filling
structure may be filled with a hardenable medium by a physician using a
syringe, pump or other filling device. Once the filling structure is
filled with hardenable medium 4104, the filling tube 4106 may be
retracted and pulled away from the filling structure 4102. In some
circumstances, the hardened filling medium 4104 may form a plug or tail
4108 that extends outside of the filling structure 4102. This is
undesirable since the tail 4108 could break free and migrate or it could
puncture or otherwise cause trauma to adjacent tissue. FIG. 41B
illustrates the remaining tail 4108 after the filling tube 4106 has been
released from the filling structure 4102. One embodiment that minimizes
or eliminates this challenge is seen in FIG. 42. In FIG. 42, the distal
portion of the filling tube 4202 has a distal port 4206 and a plurality
of side ports 4204 for delivering the hardenable medium to the filling
structure. Additionally, the distal end of the filling tube 4202 has a
tapered and rounded tip which reduces the diameter of the plug once
hardened, creating a break point when the plug is removed. FIG. 43
illustrates retraction of the filling tube away from the filling
structure 4208 after hardening of the filling medium 4210. Because the
filling medium is provided by multiple ports, several smaller plugs 4212
result and because of their smaller size, they easily break away from the
filling material 4210 in the filling structure 4208 without leaving sharp
protrusions. The polymer plugs remain inside the fill tube and break at
the ports, instead of leaving a protruding tail. Additionally, having
multiple ports 4204 is advantageous since the filling structure 4208
could be drawn into the lumen and block the distal portion 4206 during
draining of the filling structure which can involve the use of a vacuum.
The additional ports 4204 allow filling medium to be removed and/or
delivered even if the distal port 4206 is blocked.

[0137] A double filling tube may be used to avoid some of the challenges
discussed above. In FIG. 45A an outer filling tube 4502 has an inner
filling tube 4504 extending along its length. The distal ends of both
filling tube are disposed in the filling structure 4508. Filling medium
4506 can be delivered to the filling structure 4508 first, via the inner
filling tube 4504. The inner filling tube may be retracted from both the
filling structure 4508 and the outer filling tube 4502 after filling
material has been delivered 4508 as seen in FIG. 45B. The filling
structure does not always completely fill up with filling medium due to a
number of reasons such as viscosity, stagnation around the filling tubes,
etc. More commonly, the filling structure may not be completely filled up
because the physician may not infuse an adequate volume of filling
medium. Thus there may be unfilled regions 4510. Additional filling
medium 4506 may be added to the filling structure 4506 using the outer
filling tube 4502 or a new inner filling tube may be advanced through the
outer filling tube 4502. This allows the unfilled regions 4510 to be more
completely filled as seen in FIG. 45C.

[0138] The filling tubes may have many geometries. They may be round,
rectangular or other configurations. Generally, it is preferred that the
filling tubes have a low profile in order to maintain a low delivery
diameter of the entire system. For example, in FIG. 46A the filling tube
4608 has a width greater than its height. This allows the filling tube to
more easily fit in the annular space between the inner surface of a
filling structure or outer sheath 4610 and the endoframe 4604 which
mounted over a balloon 4606 on a delivery catheter 4602. FIG. 46B
illustrates nesting of an inner filling tube 4614 in an outer filling
tube 3612 with an optional wire mandrel or stylet 4616 which may be used
to prevent kinking of the filling tubes. In some embodiments, a filling
tube 4614a may have a separate lumen 4618 for a stiffening mandrel. FIG.
47A illustrates an exemplary embodiment of a delivery system where the
filling structure 4702 is axially separated from the endoframe 4712 and a
sheath 4704 covers both during delivery. The endoframe 4712 is mounted
over a balloon 4710 coupled to a catheter shaft 4708. FIG. 47B
illustrates a cross section of FIG. 47A taken along the line B-B and
highlights the low profile filling tube 4706 in the annular space between
the sheath 4704 and the endoframe 4712. Once the sheath 4704 is retracted
and the endoframe is advanced into the filling structure 4702, pressure
in the filling tube 4706 will force open the filling tube 4706 and permit
greater fluid flow.

[0139] It can be challenging to maintain an airtight seal between the
filling structure and the removable filling tube. Additionally, when the
filling medium hardens, it can be challenging to separate the filling
tube from the filling structure after in situ curing. FIGS. 39A-39C
illustrate one embodiment that facilitates separation of the filling tube
from the filling structure while maintaining the required airtight seal.
In FIG. 39A a filling tab 3904 is attached to filling structure 3902. The
filling tab 3904 may be the same material as the filling structure 3902
or a different material. The filling tab may be welded, bonded, integral
with, or otherwise attached to the filling structure. Filling tab 3904
has a perforation 3906 in it to allow for easy separation. Filling tube
3908 runs through filling tab 3904. A duck bill valve (not illustrated)
or other one-way valve may also be incorporated into the fill tab to
prevent filling medium leakage. After the filling structure 3902 has been
filled and hardened, filling tube 3908 is pulled away from the filling
structure 3902. The perforation 3906 allows the fill tab to easily tear
away from the filling structure as seen in FIG. 39B and then the fill
tube is removed from the filling structure, leaving only a small portion
of filling tab 3904 connected to the filling structure 3902, as
illustrated in FIG. 39C. In some situations, it may be advantageous to
provide some slack in the fill tab. For example, when the filling
structure is coupled with the fill tube 3908 using a tether 4006,
lockwire 4004, constrictor knot 4008, tether loop 4010 (such as described
above), the fill tab may be corrugated 4002 or additional material may be
bunched together to allow expansion. The corrugation 4002 provides some
slack in the fill tab 3904 to prevent unwanted detachment of the fill
tube 3904 at the perforation 3906 when the fill tube 3908 is moved
relative to the filling structure 3902. Once the lockwire 4004 is removed
from the tether 4006, the tether 4006 is de-coupled from the tether loop
4010 and then the fill tab 3904 may be separated at the perforation 3906.

[0140] Various modifications of the protocols described above will be
within the scope of the present invention. For example, while some of the
scaffolds have been shown as being delivered at the same time as
deployment of the filling structure(s), it will also be possible to
deliver the scaffolds after deployment of the filling structures. The
scaffolds could be delivered on the same or different delivery
catheter(s) used to deliver and/or shape the filling structures. The
scaffolds could then be expanded before, during or after filling the
filling structure.

[0141] Pressure monitoring can also be performed at various stages of the
aneurysm repair procedure to help control the filling process of the
filling structure. The monitoring of pressures serves to reduce the risk
of dissection, rupture or damage to the aneurysm from over-pressurization
and also can be used to determine an endpoint for filling. Monitoring can
be done before, during or after filling and hardening of the filling
structure with filling medium. Specific pressures which can be monitored
include the pressure within the internal space of the filling structure
as well as the pressure in the space between the external walls of the
filling structure and the inner wall of the aneurysm. A composite
measurement can also be made combining pressures such as those measured
within the interior space of the filling structure, together with that in
the space between the external walls of the structure and the aneurysm
wall or other space at the aneurysm site and an external delivery
pressure used by a fluid delivery device, such as a pump or syringe, to
deliver the filling medium. Control decisions can be made using any one
of these pressure measurements or a combination thereof. U.S. patent
application Ser. No. 11/482,503 (Attorney Docket No. 025925-001410US)
discloses a number of pressure measuring embodiments, the entire contents
of which are incorporated herein by reference.

[0142] For example, in FIG. 48A, an endoframe 4802 and filling structure
4808 are positioned in the aneurysm AAA. After preliminary expansion of
the endoframe 4802 and filling of the filling structure 4803 with saline
or other fluid, contrast media may be injected into the aneurysm and
observed under fluoroscopy. If a leak is observed 4806 around the filling
structure, the physician may add additional saline or fluid to the
filling structure until the leak is no longer observed as illustrated in
FIG. 48B. The saline may then be removed from the filling structure. The
volume of filling medium and pressure used to obtain this result are
recorded and then used when the filling structure is filled with the
hardenable filling medium. An exemplary embodiment of a delivery system
capable of treating the aneurysm and providing the contrast media to the
aneurysm is illustrated in FIG. 49. In FIG. 49, a filling structure 4906
having a filling tube 4914 is mounted over an endoframe 4914 which in
turn is disposed over a balloon 4916 coupled with the delivery catheter
shaft 4918. A wire 4910 is coupled with a nosecone 4908 on the distal end
of the delivery catheter 4918. The wire 4910 is used to guide an
angiography catheter, here a single lumen tube 4912 around the filling
structure 4906. During delivery to the aneurysm, the entire system is
housed in a delivery sheath 4902. While disposed in the sheath, the
angiography catheter 4912 is proximal to the filling structure 4906 in
order to keep profile to a minimum. Once near the device has been
advanced to the aneurysm, the sheath 4902 may be refracted proximally
thereby exposing the angiography catheter and filling structure. The
angiography catheter 4912 may be advanced distally over the wire 4910 so
that contrast media may be delivered upstream of the filling structure or
between the aneurysm wall and the filling structure.

[0143] Similar to the filling tube, the angiography catheter should also
have a low profile but it's lumen should also have as large a
cross-sectional area in order to allow easy, low pressure delivery of
contrast media at very high flow rates, 500-1,000 cc/minute. FIG. 50A
illustrates one possible embodiment for an angiography catheter. In FIG.
50A, the angiography catheter 5010 has a flat, crescent shaped profile
that lays flat and can fit in the annular space between the scaffold 5006
and the filling structure 5008. The scaffold 5006 is carried by a balloon
mounted near a distal end of the delivery catheter 5002. FIG. 50B
illustrates another embodiment where the delivery catheter 5002 includes
a guidewire lumen. The lumen is large enough to accommodate a guidewire
GW and still allow delivery of contrast media. In some embodiments, the
distal end of the catheter 5002 may include a nosecone 5012 having side
ports 5014 that allow the contrast media to exit laterally, as well as
the distal port 5016.

[0144] In an exemplary method of deploying a filling structure and
scaffolding, pressure monitoring may be utilized in the following way.
After two filling structures have been delivered to the treatment site,
both scaffolds are radially expanded to help create a lumen for blood
flow through the filling structure across the aneurysm. Using data from a
patient's computerized tomography (CT) scans, a fill volume of the
aneurysm treatment site may be estimated and then divided by two, half
for each of the two filling structures. This represents the baseline
filling volume for each filling structure and is the minimum volume of
filling material to be injected into each of the filling structures.
Syringes or other injection devices coupled with a pressure gage may be
used to optionally pre-fill each filling structure with contrast material
using the baseline volume and the resulting baseline fill pressure may be
noted. This allows unfurling of the filling structure and provides a
preliminary assessment of how the expanded filling structures fit into
the aneurismal space. Once this is accomplished, the contrast material is
removed from the filling structures. Again using the patient CT data, a
functional fill volume may be determined. This volume is a percentage of
the aneurysm volume obtained from the CT data, or it may be a
predetermined number and is the volume of filling material that
effectively seals and excludes the aneurysm. Functional fill pressure
will be the pressure at which the functional fill volume is attained. A
polymer fill dispenser may then be used to fill each filling structure
with the functional fill volume and the functional fill pressure is
noted. While holding the functional fill volume and pressure, the filling
structure may be observed under fluoroscopy to check for proper
positioning, filling and the absence of leakage across the aneurysm. If
leaks are observed, additional polymer may be added to the filling
structures until the leaks are prevented or minimized. Excessive
additional polymer should not be added to the filling structure in order
to avoid exceeding a safe fill volume or safe fill pressure. Once the
physician is satisfied with the filling and positioning of the filling
structures, stopcocks to the filling structures may be closed to allow
the polymer to harden and then the delivery devices may be removed from
the patient.

[0145] FIGS. 13A-13D illustrate an exemplary method of directly monitoring
pressure in the filling structure to help ensure that it is properly
inflated relative to the aneurysm. In FIG. 13A, a filling structure 475
is placed in the aneurysm A and scaffolding 478 provides support to the
lumen created by filling structure 475 so that blood may flow from above
the aneurysm into the iliac arteries IA A syringe 482 containing a
filling material such as polyethylene glycol (PEG) is fluidly coupled to
the filling structure 475 via fluid line 480. Filling pressure may be
monitored in a number of ways including using a pressure gage 484 coupled
to syringe 482, a graphical pressure monitor 486 or a blood pressure cuff
488. In FIG. 13B, as syringe 482 is actuated, the pressure will spike and
the PEG will be injected into the filling structure 475. A pressure
relief valve may be used to eliminate or reduce the spiking or electronic
filtering may be used to remove the unwanted spike. Due to the viscosity
of the PEG, as the polymer is being injected, the pressure will rise in
the syringe 482 as measured by gage 484 relative to the pressure in the
filling structure 475 as measured by gage 492 and also relative to the
blood pressure as indicated by gage 490. This pressure will rise until
high enough to move the PEG through the fluid line 480 into the filling
structure 475 against the pressure of the blood 490. During filling,
filling pressure 484 measured at the syringe 482 by gage 484 is
equivalent to blood pressure measured at gage 490 and within filling
structure 492, and this is illustrated in FIG. 13C. As the filling
structure 475 fills and begins to expand into engagement with the
aneurysm wall A, filling pressure measured by gage 484 will increase
again. This time syringe pressure will also match pressure in the filling
structure 492, both of which will be greater than the blood pressure 490,
as seen in FIG. 13D.

[0146] In addition to actual pressure monitoring by gages and graphical
displays, etc., other pressure indicators may also be used to facilitate
determining the filling status of the filling structure. FIGS. 14A-14C
show an exemplary embodiment employing a relief valve. In FIG. 14A, a
filling device 502 is used to fill filling structure 506 via fluid line
504. As filling device 502 is actuated, fluid will be delivered to the
filling structure 506. Initially, there will be a pressure spike at the
filling device 502 end of the system and because of this spike, the
higher pressure drives the fluid filling medium into the filling
structure 506. The pressure spike also makes it challenging to use an
over-pressure relief valve to prevent over pressurizing the filling
structure. However, a relief valve may be located closer to the filling
structure end thereby reducing the potential for unintentional bleeding
of the system due to pressure spikes. In FIG. 14B, a relief valve 508 is
coupled to filling structure 506. The relief valve is preset to a certain
pressure such that beyond the preset pressure, any additional filling
material will bleed out of the filling structure. While the relief valve
may be adjacent the filling structure, preferably the filling material
will be vented toward the proximal end (handle end) of the catheter,
outside the body. This keeps potentially dangerous fluids or other
filling material from being introduced into the body. In another
embodiment seen in FIG. 14C, when fluid bleeds out of relief valve 508 it
fills a reservoir 512 which may be disposed either in or alongside
catheter shaft 510. As reservoir 512 fills with filling medium, it is
observed under fluoroscopy or other imaging modalities and when filled,
the operator knows to stop filling the filling structure 506.

[0147] While the use of a pressure relief valve such as described with
respect to FIGS. 14A-14C can be advantageous, it also can present
challenges. For example, in FIG. 25A, a pressure relief valve 804 is
placed in between a filling device 802 and the filling structure 808 with
pressure gages 806, 810 positioned to monitor pressure at the pressure
relief valve 804 and at the filling structure 808. Once the filling
device 802 is actuated, pressure in the system will increase
significantly which can trip the relief valve 804 into venting the excess
pressure as seen in FIG. 25B before the filling structure is pressurized
as seen in gage 810. Thus, it will be very difficult to fill the filling
structure 808 since most of the filling material will be vented out of
relief valve 804. FIGS. 26A-26C illustrate a potential solution for this
challenge. In FIG. 26A, a four-way, 3 port stopcock 812 is placed in
between the filling device 802 and the filling structure 808. Prior to
actuating the filling device 802, stopcock 804 is adjusted so that flow
is turned off to the pressure relief valve 804. Then, filling device 802
may be actuated and stopcock 804 may be adjusted to turn flow on in all
directions. By turning the stopcock 804 off during actuation of filling
device 802, the relief valve will not be exposed to pressure spikes,
thereby preventing unwanted venting. FIG. 26A shows the stopcock adjusted
to turn flow off to the pressure relief valve 804. FIG. 26B shows
actuation of filling device 802 with the stopcock 812 still adjusted to
stop flow to pressure relief valve 804. FIG. 26C shows stopcock 812
adjusted to allow flow in all directions. Pressure gages 806, 810 and 814
show relative pressure at various positions between filling device 802
and filling structure 808.

[0148] Some embodiments do not utilize a pressure relief valve and
therefore other ways of masking the pressure line from pressure spikes
are also desirable. For example, when an electronic pressure transducer
is used, a low pass filter may be used to eliminate the pressure spike
observed during actuation of the filling device. Additionally, electronic
recording devices may be set to calculate and display the average
pressure over a longer period of time (e.g. sample pressure over 20
seconds rather than 2 seconds), or sampling frequency may be reduced.
This will effectively eliminate the pressure spike or "mask" it out and
the resulting pressure display is a value that more closely indicates
pressure of the filling structure. An exemplary embodiment of a pressure
gage that masks pressure spikes is illustrated in FIGS. 51A-51B. In FIG.
51A, pressure measuring device 5104 includes an internal flexible
membrane 5106 such that when high pressure fluid is delivered from a
source such as syringe 5102, the membrane 5106 will compress and absorb
some of the pressure, thereby masking any spikes. Once the membrane 5106
is pressed against the housing 5108, it cannot deform any further and
thus higher pressures will not be transmitted to the gage as seen in FIG.
51B. One advantage of this type of pressure gage is that there are no
static areas during pressurization and thus the hardenable filling medium
cannot pool and obstruct flow.

[0149] FIGS. 15A-15B illustrate still another visual indicator that may be
used to control filling of the filling structure. In FIG. 15A, a filling
device 502 is fluidly coupled to filling structure 506 via fluid line
504. A mechanical pressure indicator 514 is coupled with filling
structure 506. The mechanical pressure indicator 514 has two positions, a
first closed position as seen in FIG. 15A and a second open position see
in FIG. 15B. The indicator springs open from the closed to opened
position at a predetermined pressure value. The indicator is radiopaque
and thus may be seen under fluoroscopy. Thus, when the indicator pops
out, the operator knows that the filling structure 506 has reached a
certain pressure and/or volume.

[0150] Placing a fluid filled balloon tipped catheter in the space between
the filling structure and the aneurysm wall allows the pressure exerted
by the filling structure against the aneurysm wall to be measured, and
this is illustrated in FIGS. 16A-16B. In FIG. 16A, a partially filled,
compliant balloon tipped catheter 524 is placed between an outer wall of
filling structure 520 and an inner wall of the aneurysm A. The balloon
catheter 524 may be deployed separately from or together with the filling
structure deployment catheter. The balloon 524 may be filled with saline,
carbon dioxide or like fluids. The catheter 524 is fluidly coupled with a
pressure monitor such as gage 522 via a fluid line 526. At neutral fill
volumes, the pressure of the blood is transmitted through the balloon
524, along fluid line 526 to pressure monitoring device 522, here a
pressure gage. As the filling structure 520 is filled with a hardenable
material, it will begin to press the balloon 524 against the aneurysm
wall, squeezing it and thus exerting a higher pressure which is
transmitted along fluid line 526 to pressure gage 522, as seen in FIG.
16B. Thus, an operator may continue to fill the filling structure 520
until gage 522 indicates a desired pressure, thereby demonstrating
adequate contact between the filling structure 520 and aneurysm wall.

[0151] In addition to monitoring pressure of a balloon 524 placed between
the filling structure and the aneurysm wall, other pressure indicators
may be used to determine when to stop filling the filling structure. FIG.
17A shows how inwardly directed pressures exerted by an expanding filling
structure and an aneurysm wall are directed against a balloon 546 coupled
to pressure gage 544 via fluid line 542. This is similar to the
embodiment previously discussed in FIGS. 16A-16B. However, in FIGS.
17B-17C, the pressure gage 544 is substituted with a spring loaded
pressure indicator 544. Balloon 546 may be partially filled and
preferably has a flat section that may be placed in the space between an
outer wall of a filling structure and an inner wall of the aneurysm and
is fabricated from a compliant material in order to provide accurate
pressure feedback. As the filling structure expands and begins to
compress the balloon 546 against the aneurysm wall, balloon 546 is
compressed. The pressure transmitted by fluid line 542 to spring loaded
pressure indicator 544 increases. However, the spring mechanism in
indicator 544 resists the force until a predetermined value is reached.
In FIG. 17C, once the predetermined value is exceeded, the spring
collapses and a pin pops out of the indicator housing, alerting the user
that the filling structure has been filled or that a desired pressure has
been obtained. Different springs may be used in order to adjust the
indicator to different pressure set points. In alternative embodiments,
other compression mechanisms other than springs may be used.

[0152] The balloon 546 and pressure indicator 544 may be integrated with a
filling mechanism or the two may be separate from one another. FIGS.
18A-18B illustrate a combined filling mechanism with pressure indicator
that serves as a lockout mechanism to prevent overfilling of the filling
structure. In FIG. 18A, a gun-like filling device 552 comprises a handle
554 for actuating the filling device 552. As handle 554 is actuated by
squeezing, filling material is discharged from a reservoir through a
filling tube into the filling structure. A rack 556 having teeth is
coupled with handle 554 to provide an operator with tactile feedback so
that the operator knows how far handle 554 has been actuated. A locking
mechanism 560 similar to the pressure indicator described above with
respect to FIGS. 17A-17C is also coupled with filling device 552. In this
embodiment, when pressure from fluid line 558 coupled to the filling
structure or a balloon catheter exceeds a predetermined value, plunger
562 springs out of the locking mechanism 560 and engages one of the teeth
on rack 556, thereby preventing further actuation of handle 554. Thus,
filling mechanism 552 may be used to fill the filling structure but
without overfilling it.

[0153] Instead of a separate balloon catheter placed between the filling
structure and aneurysm wall, the filling structure may include a separate
compartment that acts like the balloon catheter previously described in
FIGS. 16A-16B. FIG. 19A illustrates a filling structure 576 having a
separate compliant compartment 578. Compartment 578 may be pre-filled
with a fluid such as saline or carbon dioxide. As filling structure 576
is filled and expands into the aneurysm wall, compartment 578 will be
compressed and pressure therein will increase. Pressure in compartment
578 may be monitored via fluid line 580 by any number of methods
including using a gage, a display or the like. This embodiment saves the
operator from having to deliver a balloon catheter like that of FIGS.
16A-16B to the site of the aneurysm. FIG. 19B illustrates a side view of
the embodiment in FIG. 19A.

[0154] FIG. 19C illustrates how the filling structure 576 may include a
compliant balloon-like member 578 for monitoring pressure between the
filling structure and the aneurysm wall. In this embodiment, the
balloon-like member 578 includes upper and lower arms 582 that
circumferentially extend around all or a portion of the filling structure
576. The arms 582 allow contact between different parts of the filling
structure to be monitored thereby preventing over inflation in one region
and underinflation in another region. A fluid line 580 allows the
balloon-like member 578 to be coupled with a pressure monitoring device.
FIG. 19D illustrates still another embodiment of a filling structure
having multiple separate compartments 584 located at several different
points around filling structure 576. Similar to the embodiment of FIG.
19C, having multiple compartments allow filling of the filling structure
to be assessed at several locations to ensure uniformity of filling. Each
compartment may monitor pressure independently of the other compartments
or they may be fluidly coupled together.

[0155] The scaffolding itself may also be used to indicate the filling
status of the filling structure. In FIG. 20A, a filling structure is
disposed over scaffold 604. Scaffold 604 has regions 606 which are
designed to collapse at a lower radial pressure than the rest of the
scaffold. Thus, when filling structure 602 is filled, it will exert a
force against scaffold 604. The weakened regions 606 collapse inwardly
slightly, without substantially occluding the lumen for blood flow,
thereby forming a series of peaks and valleys which are visible under
fluoroscopy. This is illustrated in FIG. 20B. An operator may therefore
use this to monitor the extent of filling in the filling structure 602.

[0156] In still another embodiment, the balloon used to radially expand
the scaffolding may also be used to monitor pressure. In FIG. 21, a
delivery catheter 610 comprises an expandable balloon 618 disposed on a
distal end of the catheter shaft and a scaffolding 614 is disposed
thereover. Once the filling structure 616 is advanced into the aneurysm
it may be filled. Balloon 618 is partially expanded into engagement with
the filling structure 616. As the filling structure enlarges, it begins
to compress the balloon 614. Catheter 610 transmits the pressure from
balloon 616 to a pressure gage 612 so that the operator may monitor
filling pressure. Thus, the operator may stop filling the filling
structure when a predetermined pressure value is obtained. The
scaffolding 614 may then be fully expanded either before, during or after
filling the filling structure. The balloon 618 is then deflated and the
delivery catheter 610 is removed from the aneurysm.

[0157] Other embodiments may control filling of the filling structures by
using either a balloon on the delivery catheter or the filling structures
themselves. For example, in FIGS. 27A-27B, two filling structures 852,
854 are positioned in the aneurysm AAA and partially filled with a
filling device 862 to a predetermined volume or pressure. Balloons 856,
858 on a delivery catheter are inflated using an inflation device 860. As
the balloons expand, the partially filled filling structures 852, 854 are
pressed against the aneurysm walls, filling the aneurismal space and
excess fluid is then forced out of the filling structures 852, 854 via a
relief valve 868 seen in FIG. 27B. Scaffolds 864, 866 help maintain the
lumen after the balloons 856, 858 are deflated.

[0158] FIGS. 28A-28B illustrate another embodiment where the filling
structures themselves are used to help control their filling status. In
FIG. 28A, two filling structures 852, 854 are positioned in the aneurysm
AAA. A first filling structure 852 is at least partially filled. In FIG.
28B, the second filling structure 854 is filled so that it compresses
filling structure 852. As filling structure 852 is compressed, excess
fluid is vented from filling structure 852 via a pressure relief valve
868. This process is continued until the filling structures are
essentially symmetrical with one another as may be observed under
fluoroscopy.

[0159] While the above is a complete description of the preferred
embodiments of the invention, various alternatives, modifications, and
equivalents may be used. The various features of the embodiments
disclosed herein may be combined or substituted with one another.
Therefore, the above description should not be taken as limiting in scope
of the invention which is defined by the appended claims.